PlayStation Plus members who download and install the game will receive access to “an exclusive package of in-game currency, skins, consumables, and more” valued at over $20 until August 17.

Here’s an overview of the game, via Robot Entertainment:

In Orcs Must Die! Unchained gamers play as the powerful War Mage, magical Sorceress, or brutal Blackpaw, and can unlock a lineup of other awesome heroes; each with unique powers and abilities. The key to protecting a player’s fortress is to build an impenetrable gauntlet of traps to hack, grind, flatten, gibletize, and incinerate foes. Players may go at it alone or in teams of three, all the while ensuring that the ugly, greedy, vicious Orcs don’t make it into the Rift.

Players battle enemies across multiple game types and difficulty levels, including the classic Survival mode and Sabotage, a head-to-head party mode. Either way, players decide whether they will roast orcs in pits of lava, pound them flat with ceiling traps, or freeze and shatter them with a slash. No matter the weapons and traps players choose, it’s sure to be an orc-killing blast!